Messages in this thread | | | Date | Tue, 15 Aug 2023 11:24:53 +0100 | Subject | Re: [PATCH 0/2] iommu/iova: Make the rcache depot properly flexible | From | John Garry <> |
| |
On 14/08/2023 18:53, Robin Murphy wrote: > Hi all, >
Hi Robin,
> Prompted by [1], which reminded me I started this a while ago, I've now > finished off my own attempt at sorting out the horrid lack of rcache > scalability. It's become quite clear that given the vast range of system > sizes and workloads there is no right size for a fixed depot array, so I > reckon we're better off not having one at all. > > Note that the reclaim threshold and rate are chosen fairly arbitrarily -
This threshold is the number of online CPUs, right?
> it's enough of a challenge to get my 4-core dev board with spinning disk > and gigabit ethernet to push anything into a depot at all :) >
I have to admit that I was hoping to also see a more aggressive reclaim strategy, where we also trim the per-CPU rcaches when not in use. Leizhen proposed something like this a long time ago.
Thanks, John
> Thanks, > Robin. > > [1] https://urldefense.com/v3/__https://lore.kernel.org/linux-iommu/20230811130246.42719-1-zhangzekun11@huawei.com__;!!ACWV5N9M2RV99hQ!Oj-N3yDamuhrlNTcuL5MA2LQRVf1EwFxQU21BMXSFBR1Fb3z4H_on1uiFG0EOoYpNc-FKGeoKvw9wzEV_1TRcr4$ > > > Robin Murphy (2): > iommu/iova: Make the rcache depot scale better > iommu/iova: Manage the depot list size > > drivers/iommu/iova.c | 94 ++++++++++++++++++++++++++++++-------------- > 1 file changed, 65 insertions(+), 29 deletions(-) >
| |